Delirium

Delirium is defined as an acute change or fluctuation in mental status plus innatention and either disorganized thinkings or an altered level of consciousness at the time of evaluation. Numerous studies have described the incidence, prevalence and costly impact of delirium with regard to patients in nursing homes and hospital words, but few prospective investigations have focused on cohorts treated specifically within the intensive care unit. Several studies have now confirmed that delirium occurs in 60% to 80% of mechanically ventilated patients, though two investigations found a lower prevalence in an ICU cohort with a lesser severity of illness. Only 5% of 912 critical care professionals surveyed in 2001 and 2002 suported monitoring for ICU delirium, and yet the Society of Critical Care Medicine has recommended routine monitoring for delirium for all ICU patients. Delirium is an independent predictor of longer stay in the ICU. This article reviews the definition and salient features of delirium, its primary risk factors, a newly validated instrument for delirium assessment that is being developed for ICU nurses and physicians, and pharmacological agents associated with the development of delirium and used in its management.